package cn.tang.tframe.common.utils.crypt;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.SecretKeySpec;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.SecureRandom;

/**
 * TODO 一句话描述该类用途
 * <p/>
 * 创建时间: 15/10/21 下午4:38<br/>
 *
 * @author tanghc
 * @since v0.0.1
 */
public class AESUtil {

	/**
	 * 编码工具类
	 * 1.将byte[]转为各种进制的字符串
	 * 2.base 64 encode
	 * 3.base 64 decode
	 * 4.获取byte[]的md5值
	 * 5.获取字符串md5值
	 * 6.结合base64实现md5加密
	 * 7.AES加密
	 * 8.AES加密为base 64 code
	 * 9.AES解密
	 * 10.将base 64 code AES解密
	 * @author uikoo9
	 * @version 0.0.7.20140601
	 */

		public static void main(String[] args) throws Exception {



			String content = "我爱你";
			System.out.println("加密前：" + content);

			String key = "123456";
			System.out.println("加密密钥和解密密钥：" + key);

			String encrypt = aesEncrypt(content, key);
			System.out.println("加密后：" + encrypt);

			String decrypt = aesDecrypt(encrypt, key);
			System.out.println("解密后：" + decrypt);
		}

		/**
		 * 将byte[]转为各种进制的字符串
		 * @param bytes byte[]
		 * @param radix 可以转换进制的范围，从Character.MIN_RADIX到Character.MAX_RADIX，超出范围后变为10进制
		 * @return 转换后的字符串
		 */
		public static String binary(byte[] bytes, int radix){
			return new BigInteger(1, bytes).toString(radix);// 这里的1代表正数
		}

		/**
		 * base 64 encode
		 * @param bytes 待编码的byte[]
		 * @return 编码后的base 64 code
		 */
		public static String base64Encode(byte[] bytes){
			return new BASE64Encoder().encode(bytes);
		}

		/**
		 * base 64 decode
		 * @param base64Code 待解码的base 64 code
		 * @return 解码后的byte[]
		 * @throws Exception
		 */
		public static byte[] base64Decode(String base64Code) throws Exception{
			return new BASE64Decoder().decodeBuffer(base64Code);
		}

		/**
		 * 获取byte[]的md5值
		 * @param bytes byte[]
		 * @return md5
		 * @throws Exception
		 */
		public static byte[] md5(byte[] bytes) throws Exception {
			MessageDigest md = MessageDigest.getInstance("MD5");
			md.update(bytes);

			return md.digest();
		}

		/**
		 * 获取字符串md5值
		 * @param msg
		 * @return md5
		 * @throws Exception
		 */
		public static byte[] md5(String msg) throws Exception {
			return md5(msg.getBytes());
		}

		/**
		 * 结合base64实现md5加密
		 * @param msg 待加密字符串
		 * @return 获取md5后转为base64
		 * @throws Exception
		 */
		public static String md5Encrypt(String msg) throws Exception{
			return base64Encode(md5(msg));
		}

		/**
		 * AES加密
		 * @param content 待加密的内容
		 * @param encryptKey 加密密钥
		 * @return 加密后的byte[]
		 * @throws Exception
		 */
		public static byte[] aesEncryptToBytes(String content, String encryptKey) throws Exception {
			KeyGenerator kgen = KeyGenerator.getInstance("AES");
			SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
			secureRandom.setSeed(encryptKey.getBytes());
			kgen.init(128, secureRandom);

			Cipher cipher = Cipher.getInstance("AES");
			cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));

			return cipher.doFinal(content.getBytes("utf-8"));
		}

		/**
		 * AES加密为base 64 code
		 * @param content 待加密的内容
		 * @param encryptKey 加密密钥
		 * @return 加密后的base 64 code
		 * @throws Exception
		 */
		public static String aesEncrypt(String content, String encryptKey) throws Exception {
			return base64Encode(aesEncryptToBytes(content, encryptKey));
		}

		/**
		 * AES解密
		 * @param encryptBytes 待解密的byte[]
		 * @param decryptKey 解密密钥
		 * @return 解密后的String
		 * @throws Exception
		 */
		public static String aesDecryptByBytes(byte[] encryptBytes, String decryptKey) throws Exception {
			KeyGenerator kgen = KeyGenerator.getInstance("AES");
			SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
			secureRandom.setSeed(decryptKey.getBytes());
			kgen.init(128, secureRandom);

			Cipher cipher = Cipher.getInstance("AES");
			cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));
			byte[] decryptBytes = cipher.doFinal(encryptBytes);

			return new String(decryptBytes);
		}

		/**
		 * 将base 64 code AES解密
		 * @param encryptStr 待解密的base 64 code
		 * @param decryptKey 解密密钥
		 * @return 解密后的string
		 * @throws Exception
		 */
		public static String aesDecrypt(String encryptStr, String decryptKey) throws Exception {
			return aesDecryptByBytes(base64Decode(encryptStr), decryptKey);
		}

}
